Abstract 14249: Ectonucleoside Triphosphate Diphosphohydrolase-1 (ENTDP-1/CD39) Down-Regulates P-Selectin Expression in a Murine Model of Deep Venous Thrombosis
Background: Deep venous thrombosis (DVT) is a major health care concern in the United States. CD39 is co-localizes on the surface of endothelial cells (EC), leukocytes and platelets where it regulates platelet aggregation and leukosequestration by catabolizing adenine nucleotides. Hypoxia facilitates P-selectin (P-Sel), expression on EC during DVT. We recently demonstrated a link between CD39 expression and DVT. However, the mechanism remains unclear. We hypothesized that CD39 may exert its anti-inflammatory effects under conditions conducive to venous thrombosis in part through suppressive effects on P-sel expression.
Methods: C57BL/6 (WT) and CD39-/- mice underwent inferior vena cava (IVC) thrombosis. After 48hrs, post thrombus induction, blood was drawn via cardiac puncture and the affected segment IVC (in toto) was harvested. To additionally model the known contribution of hypoxia to venous thrombogenesis, we exposed another set of animals to normoxia (21% O2 control group) or hypoxia (6-7%FiO2 ischemic group) for 48hrs. P-Sel and CD39 Levels were measured in the vein wall via ELISA and qRt-PCR.
Results: Thrombus weights significantly increased in CD39-/- mice (4.5±.25 vs.1.83±.14, n=5, p<0.05, respectively) compared to WT mice, post 48hrs of IVC ligation. We also showed significant increase in P-Sel levels in CD39-/- DVT mice (by 52.9%, n=4, p<0.001) compared to sham operated CD39-/- mice (Fig 1). In contrast, there were no significant differences noted in P-Sel levels in WT DVT mice vein wall compared to controls(0.19±.50,n=3,p=0.1337). Furthermore, under hypoxic stress, circulating CD39 protein levels and mRNA expression significantly increased (by 98%, n=4, p<0.0001; by 59%,n=5, p<0.0001, respectively) compared to normoxic exposed mice at 48 hrs.
Conclusion: Hypoxia and DVT strongly induce vascular-protective enzyme CD39, the actions of which may mitigate inflammatory upregulation of leukocyte adhesion receptors such as P-sel.
- © 2011 by American Heart Association, Inc.